I wanted to update with one more thing. Some games allow you to choose different color palettes for the characters. You should check to see if they have one for a darker complexion. I know Arcana Heart does this, and I am pretty sure a few other fighting games do it as well.

Yuri Kellarney of Mobile Suit Gundam: The 08th MS Team is kinda tan (he's of Slavic decent if it matters). Karen Joshua is also kinda tan, at least compared to the other characters on her squad save for Terry Sanders.

I would die happy if someone cosplayed the first to a con I'm at BTW <3

Would also like to point out that Shadow the Hedgehog has a darker skin tone. So it would technically be more accurate to be tan :3 (Never understood why so many human versions of shadow depict him being white o.o)

Same can be said about Rouge and Knuckles in Sonic Adventure 2 though it seems that Sega made their skin color lighter in more recent games.

Hey um, Vaan from Final Fantasy XII and Dissidia 012 has pretty tan skin... tan enough for a medium/light tan skinned person to pull of... he's about the same as Tidus in CG but a bit darker in-game, so he's good
also, Firion form Final Fantasy II or rather, Dissidia Final Fantasy definitely has medium skin